Cheapest Stocks & Shares ISA Platforms UK (2026)
The cheapest Stocks & Shares ISA platforms in the UK currently include Trading 212, InvestEngine and Freetrade. Some platforms charge 0% platform fees, while others charge a percentage of your portfolio each year.
This guide compares the real annual cost of each platform at different portfolio sizes so you can see which ISA provider is actually cheapest for your situation.
Best Cheap ISA Platforms — Quick Verdict
| Category | Platform | Fee | |
|---|---|---|---|
| Cheapest overall | Trading 212 | 0% | Visit Trading 212 → |
| Cheapest for ETFs | InvestEngine | 0% (DIY) | Visit InvestEngine → |
| Cheapest flat-fee platform | Freetrade | £4.99/month | Visit Freetrade → |
| Cheapest full-service platform | Interactive Investor | £5.99/month | Visit Interactive Investor → |
The Cheapest ISA Platforms — 0% Fee Options
Two UK platforms charge absolutely no platform fee on their Stocks & Shares ISA:
Trading 212
No platform fee, no trading commission, and a 0.15% FX fee on international shares — one of the lowest in the market. Access UK and US stocks and ETFs from £1.
InvestEngine
Zero platform fee. You only pay the underlying ETF charges — typically 0.03%–0.20% per year. The cheapest way to build a passive ETF portfolio in a Stocks & Shares ISA.
Freetrade
Cheaper than most percentage-fee platforms for portfolios above around £20,000. Clean mobile app, commission-free trading on all plans.
ISA Platform Fees — Annual Cost by Portfolio Size
Here is exactly what you would pay each year on each platform at different portfolio sizes. Platform fees only — trading fees and fund charges (OCF) are additional.
| Platform | Fee Model | £5,000 | £20,000 | £50,000 | £100,000 | £250,000 | |
|---|---|---|---|---|---|---|---|
| Trading 212 | 0% | £0 | £0 | £0 | £0 | £0 | Trading 212 Review → |
| InvestEngine (DIY) | 0% platform | £0 | £0 | £0 | £0 | £0 | InvestEngine Review → |
| Freetrade | £4.99/mo flat | £59.88 | £59.88 | £59.88 | £59.88 | £59.88 | Freetrade Review → |
| Interactive Investor | £5.99/mo flat | £71.88 | £71.88 | £71.88 | £71.88 | £71.88 | Interactive Investor Review → |
| AJ Bell | 0.25% p.a. | £12.50 | £50 | £125 | £250 | £482* | AJ Bell Review → |
| Hargreaves Lansdown | 0.35% p.a. | £17.50 | £70 | £175 | £350 | £732* | Hargreaves Lansdown Review → |
| Nutmeg | 0.45% p.a. | £22.50 | £90 | £225 | £450 | £945* | Nutmeg Review → |
* AJ Bell and HL have tiered fees and caps — figures are estimates. Always check current fee schedules on each platform's website before opening an account.
Best Cheap ISA Platforms — Flat Fee vs Percentage Fee
The cheapest ISA platform depends entirely on your portfolio size. Percentage fees are proportional — they scale with your portfolio. Flat fees are fixed — they stay the same whether your portfolio is £10,000 or £500,000.
📉 Percentage fees are cheaper for:
Small and growing portfolios below £20,000–£24,000. If you are just starting out, a 0.25% fee on £5,000 is only £12.50/year — much less than any flat-fee platform. Percentage platforms also automatically scale down as a cost burden if your portfolio falls.
📈 Flat fees are cheaper for:
Larger and growing portfolios above £24,000–£57,000 depending on the platform. Interactive Investor's £5.99/month Core plan becomes cheaper than a 0.25% platform at around £24,000 in portfolio value — and the savings grow significantly at £50,000, £100,000, and beyond.
Cheapest ISA by Portfolio Size
Under £10,000
Best: Trading 212 or InvestEngine — both charge 0%. All other options cost more at this portfolio size. Freetrade (£59.88/year) and Interactive Investor (£71.88/year) are significantly more expensive in percentage terms for a small portfolio.
£10,000 – £50,000
Best: Trading 212 or InvestEngine — still 0%. Freetrade and Interactive Investor flat fees start to become competitive above £20,000–£24,000 versus AJ Bell's 0.25%. AJ Bell costs £50/year on £20,000 vs Freetrade's flat £59.88.
£50,000 – £100,000
Best: Trading 212, InvestEngine, or Interactive Investor — all cost less than £72/year. AJ Bell costs £125–£250/year at this range. HL costs £175–£350/year. Interactive Investor is the cheapest full-service platform by a significant margin at this portfolio size.
£100,000+
Best: Interactive Investor — the Core plan at £71.88/year is dramatically cheaper than percentage platforms at larger portfolio sizes. At £250,000, you save over £400/year versus AJ Bell and nearly £700/year versus HL. Plus plan (£179.88/year) applies above £100,000.
Hidden ISA Platform Fees to Watch For
A platform's headline fee is not always the full story. These additional charges can add up — especially for active investors or those buying international shares.
FX Fees
Charged when buying shares priced in foreign currencies (e.g. US stocks in USD). Trading 212 charges 0.15% — one of the lowest. Interactive Investor charges 0.75% on the Core plan. HL charges around 1.0%.
Dealing / Trading Charges
Some platforms charge per trade. Interactive Investor charges £3.99 per share trade (with one free monthly trade). AJ Bell charges £5.00. Trading 212 and InvestEngine charge £0.
Fund OCF (Ongoing Charge Figure)
Every ETF and fund charges an annual fee — separate from the platform fee. Typical index ETFs charge 0.03%–0.22% per year. This is charged by the fund manager, not the platform, and applies on every platform.
Inactivity Fees
Most mainstream ISA platforms in the UK do not charge inactivity fees. Trading 212, InvestEngine, Interactive Investor, AJ Bell and Hargreaves Lansdown all have no inactivity charge.